A weeping South Vietnamese mother and her three children are shown on the deck of this amphibious command ship being plucked out of Saigon by U.S. Marine helicopters in Vietnam, April 29, 1975. (Photo by AP Photo)

A man carries his wife on his back as they make their way with their luggage along a flooded tunnel to catch their train, after heavy rainfall hit Jinhua, Zhejiang province, China, July 21, 2015. (Photo by Reuters/China Daily)

An undercover police officer, who had been marching with anti-police demonstrators, aims his gun at protesters after some in the crowd attacked him and his partner in Oakland, California December 10, 2014. Police said more than 100 demonstrators marched in Berkeley, California, which has a history of social activism. Under cloudy skies, turnout was smaller than earlier in the week, when demonstrators in the area threw rocks at police and shut down a major freeway. (Photo by Noah Berger/Reuters)

Tourists take a “selfie” as demonstrators burn a trash container during a May Day rally in Barcelona, Spain, on May 1, 2014. Tens of thousands of workers marked May Day in European cities with a mix of anger and gloom over austerity measures imposed by leaders trying to contain the eurozone's intractable debt crisis. (Photo by Manu Fernandez/Associated Press)

Collided passenger train cars are seen in Taebaek, South Korea, Tuesday, July 22, 2014. Two passenger trains collided head-on in eastern South Korea on Tuesday afternoon, killing one passenger and injuring dozens, fire officials said. (Photo by AFP Photo/Yonhap)

Two men fight in San Jose, Costa Rica, during the Women's Day on March 8, 2014. (Photo by Jeffrey Arguedas/EFE/SIPA Press)

An Iraqi Muslim woman walks past Christmas decorations for sale in the Shiite holy city of Najaf on December 17, 2015. (Photo by Haidar Hamdani/AFP Photo)

Julia Gracheva and Anna Speak takes photos as they attend the 10th edition of “Diner en Blanc” at Brookfield Place in Lower Manhattan September 19, 2022. The legendary all-white secret pop-up, the location of which is revealed hours before the event, draws over 5,500 guests who dress in head-to-toe white attire for an under the stars dining experience. (Photo by Timothy A. Clary/AFP Photo)